Refactor a bit.

service/taskqueue/interface.go

Index: service/taskqueue/interface.go
diff --git a/service/taskqueue/interface.go b/service/taskqueue/interface.go
new file mode 100644
index 0000000000000000000000000000000000000000..980a1bccd8d4919801593fd1d236ddf9a9d901a5
--- /dev/null
+++ b/service/taskqueue/interface.go
@@ -0,0 +1,22 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package taskqueue
+
+// Interface is the full interface to the Task Queue service.
+type Interface interface {
+	Add(task *Task, queueName string) (*Task, error)
+	Delete(task *Task, queueName string) error
+
+	AddMulti(tasks []*Task, queueName string) ([]*Task, error)
+	DeleteMulti(tasks []*Task, queueName string) error
+
+	Lease(maxTasks int, queueName string, leaseTime int) ([]*Task, error)
+	LeaseByTag(maxTasks int, queueName string, leaseTime int, tag string) ([]*Task, error)
+	ModifyLease(task *Task, queueName string, leaseTime int) error
+
+	Purge(queueName string) error
+
+	QueueStats(queueNames []string) ([]Statistics, error)
+}